Pterosaur.Net

:: Myths and Misconceptions

Through their portrayal in the media, in movies, cartoons, comics and science-fiction
stories, pterosaurs have been consistently described and depicted inaccurately. Here we
address some of the more common inaccuracies seen in the media and the popular literature.
Misconceptions about pterosaurs are not limited to popular culture however: many text
books, reference works and scientific books (generally written by people who weren’t
experts on pterosaurs) have made erroneous claims about pterosaurs, in particular about
their wing anatomy, feeding habits and body mass.

The name ‘pterodactyl’

The term ‘pterodactyl’ is sometimes used for pterosaurs, particularly by
journalists, with the implication being that the term is synonymous with pterosaur. In
fact it isn’t: the term pterodactyl—originally written ‘ptero-dactyle’—was
first used for one specific type of Upper Jurassic pterosaur, the European ctenochasmatoid
Pterodactylus, and doesn’t apply to other members of Pterosauria. It has been used
on occasion for giant short-tailed pterosaurs like pteranodontids, but this is not common
among pterosaur workers. If we used vernacular names for prehistoric animals (which,
generally speaking, we don’t), then we might well term members of the genus
Pterodactylus ‘pterodactyls’. But we don’t, so the words pterodactyl
and ptero-dactyle are pretty much redundant today.

Myth of the bat-winged pterosaur

Cartoonists, artists and film-makers have often portrayed pterosaurs as having bat-like
wings, and writers have often described pterosaur wings as ‘leathery’, or at
times as flimsy and as thin as tissue paper. Pterosaur wings were unique in that a single,
super-enlarged, particularly robust finger (the fourth finger) provided the only bony
support for the wing membrane, but subparallel fibres termed aktinofibrils were embedded
within the membrane and would have provided additional structural support. This system is
very different from that of bats, where the second, third, fourth and fifth fingers are
all involved in supporting the wing membranes. Any depiction which shows bat-like fingers
supporting a pterosaur’s wing membrane is just flat wrong (movie-makers like Ray
Harryhausen did this simply because they thought it looked cool, and because it made the
stop-motion model’s wings easier to operate).

Exceptionally preserved pterosaur fossils show us that, like bats, pterosaurs had blood
vessels and very thin muscle layers within their wing membranes. However, pterosaurs were
unique in that they also had a special air-filled layer embedded within the wing membrane,
and their blood vessel system was not simple, but large and complicated. While pterosaur
wing membranes would have been thin (with a thickness of only a few millimetres), they
were not just a single sheet of skin as used to be imagined, but relatively robust and
complicated structures that were probably resistant to tearing and damage. A pterosaur
that broke the bones of its wing would probably have been doomed, but damage to the wing
membranes might not necessarily have been so bad: bats sometimes damage their wing
membranes by snagging them on plants and debris, but holes and tears are not fatal and
soon heal up. It is also completely inaccurate to imagine pterosaur wings as leathery,
given that leather is a very heavy, relatively incompliant material.

Pterosaurs are dinosaurs

Pterosaurs are sometimes described in the media as ‘flying dinosaurs’. In
fact pterosaurs are not part of the group formally termed Dinosauria, although the
presence of various morphological characters which are shared by both groups suggest that
they are close relatives. The shared presence of a relatively long neck with
proportionally long cervical vertebrae, of an elongate tibia, and of a hinge-like ankle
joint and elongate metatarsals in the foot indicate that pterosaurs, dinosaurs and a few
other groups should be united in a clade which has been termed Ornithodira. It is inferred
from this distribution of features that pterosaurs and dinosaurs shared an ancestor that
was alive during the middle Triassic.

However, it has been argued on several occasions that pterosaurs are not close to
dinosaurs, but instead are part of an altogether different reptile group called the
Protorosauria (the only well known member of this group is the bizarre long-necked marine
form Tanystropheus). Whether pterosaurs are closer to dinosaurs or protorosaurs remains
the source of argument, but at the moment the evidence for an affinity with dinosaurs
seems better supported. It’s perhaps worth noting that one palaeontologist (Robert Bakker)
argued on one occasion (in his 1986 book Dinosaur Heresies) that pterosaurs are, in fact,
part of Dinosauria. However, this is because he used a more inclusive version of
Dinosauria than that currently favoured by other palaeontologists: his concept of
Dinosauria was essentially synonymous with Ornithodira.

Common misconceptions about size

Some pterosaurs have been portrayed in the popular literature, and in films and
cartoons, as being the wrong size. Mostly this is because certain pterosaurs—namely
Pterodactylus and Rhamphorhynchus from Upper Jurassic Europe—have
served as templates for imaginary generic pterosaurs. In the movies The Land That Time
Forgot (1975) and The People That Time Forgot (1977), for example, the pterosaurs are
Pteranodon-sized (with wingspans of 5 metres or more), but they are clearly based
on Pterodactylus, a form in which the wingspan was usually less than 1 m. Comic
stories have also depicted Rhamphorhynchus and Dimorphodon as similarly gigantic,
whereas in fact both had wingspans of less than 1.5 m.

That super-gigantic pterosaur

To date, the largest known pterosaurs are members of the Cretaceous azhdarchid group
like Quetzalcoatlus and Hatzegopteryx: these animals had wingspans of 10-12
m. However, in 2005 came the exciting news that evidence for an even larger pterosaur had
been discovered: supposedly, a wing fragment from the Jordan and a trackway from Mexico
indicated the presence of a new type of gigantic azhdarchid with an 18 m wingspan. This
news, announced at a scientific conference by a colleague who shall remain nameless, was
picked up by journalists and reported in newspapers and on radios all around the world.
Unfortunately, the evidence for this super-pterosaur turned out to be erroneous. The bone
turned out to be a piece of fossil wood and the trackway had not been produced by a giant
pterosaur, but by a predatory dinosaur. Oh well.

Pteranodontids had teeth

One of the most familiar pterosaurs, the large, crested oceanic ornithocheiroid
Pteranodon, is well known for being toothless. It was far from the only toothless
pterosaur—tapejarids, tupuxuarids and azhdarchids were toothless too. However,
cartoons and movies have often equipped Pteranodon with teeth, both in an effort to
make it look more scary, and (presumably) to make it look more alien and prehistoric than
it was. Neither pteranodontids nor their relatives the nyctosaurids had teeth, but the
great irony is that we now know of two Cretaceous pterosaurs—Ludodactylus
from the Brazilian Crato Formation and Caulkicephalus from the Isle of Wight’s
Wessex Formation—that did combine a Pteranodon-like head crest with
teeth.

Less well known is that azhdarchids—the group of Cretaceous pterosaurs that
includes Quetzalcoatlus—have also been depicted with teeth on occasion. Today
we know that azhdarchids had very elongate, toothless skulls superficially similar to
those of storks or herons, but some early reconstructions from the 1970s and 80s showed
Quetzalcoatlus with a particularly bizarre, proportionally small head. A large bony lump
was depicted on the back of its head and it was shown with small pointed teeth!

Pterosaurs could pick things up with their feet

Films and cartoons consistently portray pterosaurs as being equipped with prehensile,
strongly muscled feet with a big opposable digit: in other words, they are depicted as
superficially recalling human hands. Of course, the pterosaurs in the films and cartoons
need such feet in order to pick up the humans that they’re menacing—a tradition that
is familiar thanks to One Million Years B.C. and was even included in Jurassic Park III.
No pterosaur, so far as we know, had prehensile feet with opposable digits: in fact
pterosaur feet are generally weakly muscled, and certainly lack opposable digits.
Pteranodon—the animal which is generally shown in the movies picking people
up—was like other members of its group (Ornithocheiroidea) in having proportionally
small, slender-boned feet.

Pterosaurs have survived to the present

Unusual winged animals reported from around the world have been suggested by some
cryptozoologists and creationists to be modern-day pterosaurs that survived the
end-Cretaceous extinction event. From Africa, people have reported a semi-aquatic winged
animal called the kongamato while on New Guinea and the surrounding islands sightings are
claimed of a gigantic, bioluminescent, crested flying creature (the duah) and a smaller,
long-tailed version, the ropen. Fossil evidence demonstrates overwhelmingly that
pterosaurs did not survive beyond the end of the Cretaceous, and the sightings of
pterosaur-like animals that have been reported appear to be a combination of hoaxes and
misidentification of large birds and bats. So-called modern pterosaurs are generally ugly,
dark, carnivorous, bat-winged horrors—they sound more like imaginary generic flying
monsters than the pterosaurs we know from the fossil record.